G. Nalzhupbayeva, “Spectral properties of the iterated Laplacian with a potential in a punctured domain”, Filomat, 32:8 (2018), 2897–2900
G. Nalzhupbayeva, “Remark on the eigenvalues of the $m$-Laplacian in a punctured domain”, Complex Anal. Oper. Theory, 12:3 (2018), 599–606
Б. Е. Кангужин, “Операторы, резольвенты которых имеют сверточное представление, и их спектральный анализ”, Комплексный анализ, Итоги науки и техн. Соврем. мат. и ее прил. Темат. обз., 153, ВИНИТИ РАН, М., 2018, 94–107 ; B. E. Kanguzhin, “Operators Whose Resolvents Have Convolution Representations and Their Spectral Analysis”, J. Math. Sci. (N. Y.), 252:3 (2021), 384–398
G. Nalzhupbayeva, “Formulas for the eigenvalues of the iterated Laplacian with singular potentials”, International Conference Functional Analysis in Interdisciplinary Applications (FAIA2017), AIP Conf. Proc., 1880, eds. Kalmenov T., Sadybekov M., Amer. Inst. Phys., 2017, UNSP 050005
Gulzat Nalzhupbayeva, Niyaz Tokmagambetov, Springer Proceedings in Mathematics & Statistics, 216, Functional Analysis in Interdisciplinary Applications, 2017, 267